Climate Control seems to change temp

[jbjb]

My 04 Z-71 with climate control seems to have a mind of its own. When I start out in the am with temp set at say 75, and select defrost by pushing the defrost button everything seems okay. As truck warms up, I'll drop temp from 75 to 65 to try to cool the incoming air. That normally doesn't work because the air is not blowing directly on me, so I'll change the air delivery position to the dash. When I do this, the temp changes back to the 75 degree setting even tho I had it set on 65. What am I missing here?

And for the record, I don't have the noisey fan above the dirvers seat, but I am disappointed in the lack of automatic operation of the defrost, and the apparent need to swing the climate control temp setting to the extremes to get a change. Once on the road for a while, it settles down and works fine. I've never had CC before and may be having trouble getting used to it.

 

[Tree_Hugger]

Pick the temperature setting that seems good to you. Set it to that. (Make sure you press and hold the memory button afterwards).
Now LEAVE IT ALONE!
If you need the defrost setting press it. When you don't any more, press it again. That's it.

HTH.

It does sound as if you should have got the manual controls, rather than CC. There's quite a lot of people really want to manage it themselves....

 

[jbjb]

I'm replying to my own message--kinda like the Depatrment of Redundancy Department.

After careful research, I think I have figured out how the above mentioned temp changes happen--I have no clue at to the why.

There are apparently two ways to change into the deforst mode on a CC equiped vehicle. You can cycle thru 4 options by pressing the button below the auto button--different air outlet combo's if you will. The second way is to press the defrost button. By pressing the defrost button you get all air going to defrost; by cycling to the defrost selection with the other button, you get a combo of foot vents and defrost. But there is one additional difference. When using the cycle button, any temp changes you make are permanent, that is they apply to all four of the cycle choices. When using the defrost button any temp changes are overridden as soon as you go back to the cycle switch. I think you also get mirror defrost with the defrost button but I'm not sure.

Anyway, now I know how I'm getting 'phantom' temp changes, but I still don't know why they do it that way.